Cornell is technically a state school so can offer in-state tuition. Also, the financial aid packages at a lot of these schools (the endowments are staggering) can be incredibly generous (even for middle-class families), to the point that it might actually be comparable to a scholarship, full scholarships being as rare as they are in wrestling.
Some other points:
(1) It's much easier to get a full academic scholarship to your local state university than an athletic one anywhere, yet plenty of high-achieving students opt to go to fancy pants private schools over schools where they have been offered an academic scholarship (and vice versa).
(2) The alumni networks at these programs are incredible well represented and connected at the major wall street firms. If you stick around the program and don't f*** up, you're pretty much going to be guaranteed a job as junior trader and be well-positioned to get ahead in that particular field, which is obviously fantastic lucrative. While there are plenty of guys from other schools who find their way in, but being an Ivy League athlete makes it... easier.